1. Field of the Invention
The present invention relates to a toothbrush essentially consisting of a head having tooth-brushing bristles implanted therein, a neck having the head attached to the distal end thereof and a holder for holding the neck, wherein the neck is telescopically engaged with the holder to enable adjustment of the length of the neck to protrude from the holder. The present invention also relates to an adjustable head used in the toothbrush.
2. Description of the Related Art
Conventional toothbrushes are simply directed to cleaning furry teeth, and they come in different types in terms of the shape of the handle, the size of the head, the stiffness of bristles implanted in the head, etc. For example, some toothbrushes have curved handles, some others have small heads, and some others have bristles whose stiffness is varied from spot to spot on the head, so that users can select optimum ones in accordance with use conditions including the user's mouth size and the like.
Tooth brushing is not merely directed to cleaning teeth, but optimum oral condition can be maintained if a user selects an optimum toothbrush taking individual specificity into consideration, including the size of teeth, dentition, occlusion, intraoral volume, sex, age and dextrality or sinistrality. Accordingly, the necessity of such consideration is advocated when a user selects a toothbrush. More specifically, it should be appreciated that a toothbrush is a buccal cleaning device or oral conditioner for optimizing the oral condition and preventing harmful effects that the conventional toothbrushes frequently give.
In terms of optimization of oral condition, it is difficult for some of the conventional toothbrushes described above to meet the above requirements. Further, there is a limit for a single toothbrush to clean ones teeth entirely, and some teeth cannot be brushed sufficiently depending on the position and portion of each tooth.
In some cases, bristles implanted in the head injure the teeth or gums.